Multiple choice

Which of the following Oracle access methods is the fastest way for Oracle to retrieve a single row?

  1. Primary key access

  2. Access via unique index

  3. Table access by ROWID

  4. Full table scan

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

ROWID access is the fastest retrieval method because ROWID is the direct physical address of a row in the data file. When Oracle knows the ROWID, it can access the row in a single I/O operation without traversing indexes or scanning tables. Primary key and unique index lookups require index traversal first, then ROWID access. Full table scans read all blocks, which is the slowest method.

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